The density of free electrons in an arbitrary semiconductor in a given energy band is obtained by considering that there must be an available state in this band and by weighting it with the probability that this state is occupied. a) State the mathematical description of this carrier density, explaining the meaning of each term. b) Considering the conduction band stall, explain why the distribution of carriers as a function of energy is not monotonically increasing (or decreasing) Please explain each step as I'm having trouble in understanding this subject.

A constant diffusion current of electrons is established through a silicon semiconductor material. The value of current density is Jn= –0.8 A/cm2. The electron concentration at x=0 is n(0)=1.5x1015 cm–3. The diffusion constant of electrons and holes are 35 and 14 cm2/s, respectively . Determine the hole drift current density

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Hole mobility...

1.) Which type of semiconductor material has been doped such that the majority of its current carriers are holes? a. None of these b. P-Type Semiconductors c. Q-Type Semiconductors d. N-Type Semiconductors   2.) The outer shell of an atom can hold up to a maximum of x electrons? What is x? a. 5 b. 2 c. 4 d. 8   3.) Which device has one PN junction: a. None of these b. Resistors c. Transistors d. Diodes

a) With the aid of illustrations and using Silicon, describe what an intrinsic semiconductor material is. (b)  With the aid of illustrations and using Silicon, describe what an extrinsic N type            semiconductor material is. (c)  With the aid of illustrations and using Silicon, describe what an extrinsic P type         semiconductor material is. (d)  With the aid of illustrations, describe what happens when P and N materials are        joined/fused together and what is formed across the join. Then describe and        illustrate how the formation at the junction can be controlled. (e)   Give clear illustrations of characteristics for GERMANIUM and SILICON DIODES and          say what is the threshold value (Vt) for Silicon and Germanium.

A. Define the drift current in a semiconductor and give the mathematical expressions about both the current density of the electron drift current and the current density of the hole drift current. Define the diffusion current in a semiconductor and give the mathematical expressions about both the current density of the hole diffusion current and the current density of the electron diffusion current.